enfranchisement vs imprisonment

enfranchisement

noun
  • The investiture with any of several municipal privileges 

  • the conversion of a copyhold estate into a freehold estate 

  • The act of enfranchising 

  • A release from slavery 

imprisonment

noun
  • A confinement in a place, especially a prison or a jail, as punishment for a crime. 

How often have the words enfranchisement and imprisonment occurred in a corpus of books? (source: Google Ngram Viewer )